The basic function of an e-commerce website is to enable businesses to sell products or services online to customers. An e-commerce website typically includes the following basic functions:

1. Product catalog: An e-commerce website will typically have a catalog of products or services that the business offers for sale. The catalog will include product descriptions, prices, and images.
2. Shopping cart: A shopping cart is a software program that allows customers to select products they want to purchase and add them to a virtual cart. The shopping cart will typically calculate the total cost of the items and provide the customer with an estimate of the shipping and tax costs.
3. Payment gateway: An e-commerce website will typically have a payment gateway that allows customers to securely enter their payment information and complete their transaction. The payment gateway will typically process credit card transactions and verify that the payment has been made.
4. Order fulfillment: Once a customer has completed their transaction, the e-commerce website will typically generate an order that needs to be fulfilled. This may involve shipping physical products to the customer or delivering digital products or services electronically.
5. Customer account management: An e-commerce website will typically allow customers to create accounts to save their billing and shipping information, view their order history, and track their shipments.

Overall, the basic function of an e-commerce website is to provide a convenient and efficient way for businesses to sell their products or services online, while also providing customers with a user-friendly and secure shopping experience.